Use of Biodiesel in a Transit Fleet (2007)

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39 SUMMARY AND CONCLUSIONS After reviewing the literature and experiences of those using biodiesel, it is apparent that biodiesel is a viable complement to petroleum diesel for use in buses. Biodiesel offers too many benefits for transit agencies to ignore. Unlike petro- leum diesel, biodiesel is a renewable energy source produced domestically that can both reduce dependency on foreign oil and provide greater energy security. These factors alone make biodiesel worth considering. Biodiesel also provides significant environmental bene- fits. The plants used to make biodiesel displace atmospheric carbon dioxide through the natural growing process, and the higher oxygen content of biodiesel reduces emissions by providing more complete combustion. Studies regarding NOx emissions, however, present various findings. Some show a slight increase in NOx, others a slight decrease, whereas one study shows biodiesel having no effect on emissions at all. The variations highlight the need for more conclusive research, especially focused on 2007 and newer diesel engines equipped with particulate filters, and engines fitted with NOx reduction equipment needed to meet 2010 EPA requirements. Unlike other alternative fuels, biodiesel has virtually no safety or handling concerns other than those normally associ- ated with diesel, nor any extensive infrastructure requirements. Biodiesel does, however, have a series of characteristics and related potential issues that must be understood and actively managed to achieve a trouble-free transition. The ease with which biodiesel can be ordered, poured into existing diesel fuel storage tanks, dispensed into buses, and easily used in those buses is one of its biggest downsides. Because biodiesel can be used so easily as an additive to diesel, it is also easy to overlook the steps needed to prevent difficulties. Troubles may manifest quickly, over time, or not at all. Agencies should not, how- ever, just hope for the best. None of the procedures needed to prevent problems associated with the use of biodiesel are especially difficult to put in place, and pale in compar- ison to the efforts needed to implement other alternative fuels. Overlooking these basic procedures, however, could result in problems. Worse yet, ignoring the relatively sim- ple implementation procedures could give biodiesel a rep- utation it does not deserve. The most significant conclusion drawn from this study is that users must actively manage biodiesel to be effective. Given the complexities associated with advanced bus tech- nologies and the host of other issues that maintenance man- agers continually face, managing the implementation of biodiesel becomes yet another task added to an already long list. However, if an agency decides to move forward with biodiesel it must become thoroughly familiar with the fuel and the implications associated with its use, and commit the appropriate effort and resources. The areas of biodiesel use that need to be managed to ensure its successful implementation have been discussed in detail throughout this synthesis. They are summarized here, followed by a section on recommendations to assist agencies with their implementations. • B100 Versus Lower Blends B100 is pure biodiesel, which can be used as is or mixed with diesel to form various blends. The higher the biodiesel content the greater the benefits in terms of reducing dependence on nonrenewable and foreign-based petroleum diesel, reduced emissions, added fuel lubricity, and so forth. However, the greater the biodiesel percentage the more actively the fuel implementation needs to be managed in a fleet environment to avoid potential facility- and vehicle-related problems such as voiding engine warranty, cold weather issues, material com- patibility issues, problems related to the cleansing action of the fuel, fuel economy penalties, and potential vehicle perfor- mance impacts. • Warranty All engine manufacturers provide warranty coverage based on using fuels and lubricants that conform to recommended char- acteristics. This applies to traditional diesel as well as biodiesel. When it comes to biodiesel use, engine original equipment manufacturers typically have very explicit require- ments for the fuel specification and the amount of biodiesel blended with diesel. Some limit biodiesel to B5, whereas oth- ers approve B20 and higher levels. Agencies that do not keep abreast of developments and fail to conform to engine requirements risk losing warranty coverage. This applies to the fuel delivery system and other components if the manufacturer can prove the fault is related CHAPTER SIX PROJECT RESULTS, CONCLUSIONS, AND RECOMMENDATIONS

to biodiesel use. Agencies therefore must consider the bene- fits of using biodiesel against potential warranty risks. • Biodiesel Specifications and Quality Biodiesel is not officially biodiesel unless it meets the ASTM D6751 specification. Although this specification defines acceptable fuel characteristics and performance for B100, and ASTM D975 provides the specification for petroleum diesel, neither address the blends created (e.g., B10 and B20) when the two are mixed. ASTM is, however, developing a standard for mixed biodiesel blends, though it is not yet finalized. In an attempt to help further this process, the Engine Manufacturers Association has released its test specification for B20, which could be used by agencies in the interim. It is important to note that any biodiesel fuel that does not meet ASTM D6751 should not be used in diesel engines, period! Neither ASTM specification D6751 or D975 addresses quality control measures after biodiesel is produced. This is however done by the National Biodiesel Accreditation Pro- gram, and is known as the BQ-9000 standard. The standard addresses quality control measures for storing, sampling, test- ing, blending, shipping, distributing, and fuel management, and is to be used as a companion to ASTM D6751. • Blending, Delivery, and Storage Depending on availability, biodiesel can be pipe-blended by the supplier and delivered as a premixed, ready-to-use product similar to diesel fuel. Until biodiesel becomes more popular and readily available as a ready-mixed product that meets in- dividual agency requirements, users will needs to blend bio- diesel inside the tanker truck that delivers the fuel or within the agency’s storage tanks. Splash blending is where heavier B100 is poured atop diesel fuel already contained inside the tank, with gravity doing the mixing as the B100 disperses to the tank’s bottom. In-tank blending is similar to splash blend- ing (the terms are often used interchangeably), but involves some form of external agitation to achieve the desired concen- tration. In-tank blending agitation could be achieved by: • Mechanical blending means such as a rotating device placed inside the tank, • Splash blending B100 into a tanker truck containing diesel and letting the movement of the truck during delivery mix the two fuels, or • Alternating the delivery of the two fuels into the storage tank so that the force of the fuels entering the tank one after the other does the in-tank blending. In no case should B100 be poured first into an empty tank, because its heavier weight will cause it to remain at the bot- tom and not mix well with the lighter diesel above it. Biodiesel can be stored in the same bulk storage tanks as diesel, in separate tanks, purchased and dispensed at off-site 40 retail filling stations, or delivered and filled directly to indi- vidual buses onsite by the supplier (wet hose method). Biodiesel’s increased ability to grow bacteria in the presence of water typically requires additives to control this. Addition- ally, biodiesel’s higher cloud point (ability to freeze or gel at higher temperatures than diesel) may require additional pro- cedures. Although more consistent temperatures offered by underground storage tanks mitigate many of the cold weather issues, biodiesel still needs to be delivered warm enough to the site to prevent gelling when the fuel is exposed to ambient air temperature while being poured into the storage tank. • Cold Weather Operation The characteristic of biodiesel to freeze or gel (thicken) at higher temperatures than diesel gives it the potential for cold weather problems not only with delivery, storage, and dis- pensing, but with vehicle drivability. Typical cold weather problems occur when biodiesel is delivered or stored at tem- peratures near or below the fuel’s cloud point. When this occurs, the thickened fuel will cause dispensing filters to clog, which can slow down or stop the fuel from flowing. The same could occur with the bus, which can cause the vehicle to run poorly or even shut down. Users can eliminate all of these potential problems by keeping the temperature of the biodiesel safely above its cloud point. This can be managed by cold weather additives, adding kerosene to the biodiesel, switching to No. 1 diesel as the base fuel, or by switching to a lower percentage of biodiesel (e.g., B5 or B10) in the winter, all of which effec- tively raise the cloud point of biodiesel to prevent gelling. The temperature of biodiesel during delivery, however, may need to be monitored depending on ambient temperature. • Materials Compatibility Biodiesel, especially B100, is known to be incompatible with certain materials found in facility fuel storage and dispensing equipment, and with bus onboard fuel delivery systems. Soft materials used to make gaskets and seals such as natural or nitrile rubber compounds and other materials are particularly vulnerable to B100, whereas Teflon, Viton, and Nylon have very little reaction to biodiesel. Harder materials such as brass, bronze, copper, lead, tin, and zinc may be oxidized by biodiesel to the point where it creates solids that can contam- inate fuel delivery systems. Stainless steel, carbon steel, and aluminum are generally not affected. Biodiesel blends of 20% and lower have much less effect on these materials; information and advice concerning mate- rial compatibility is available from engine and facility fuel- ing manufacturers. Agencies should remember that biodiesel accidentally spilled in the engine compartment or elsewhere on the vehicle may degrade hoses, wiring, and other compo- nents not designed to come in contact with fuel. Workers should immediately clean up any biodiesel spilled on these

41 components or on paint and decals during daily fueling to avoid potential damage. • Cleansing Effect Biodiesel is a natural solvent that will dissolve and dislodge accumulated sediments formed over time in both vehicle and facility fuel delivery systems. Once dissolved, the sediments can travel within the fuel to clog dispensing filters. These sediments can also wreck havoc with fuel injector and other bus fuel system components. The problem is exacerbated if the fuel begins to gel in colder weather, creating two poten- tial sources for fuel delivery problems. The level of biodiesel’s cleansing action depends on two factors: the amount of sediment that has formed in the fuel system over time, and the amount of biodiesel blended with the diesel fuel. Higher biodiesel concentrations have a greater cleansing action; older vehicle and facility fueling systems tend to have a greater buildup of sentiments. This combination is sure to present problems if not managed. Again, users can effectively manage these potential prob- lems monitoring fuel filters for debris and, if needed, clean- ing or flushing fuel systems to remove sediments. Once re- moved, biodiesel will generally keep the sediment from reappearing. Agencies should note, however, that increasing to stronger concentrations can cause additional debris to be dislodged. • Costs As with diesel, the price of biodiesel is constantly changing. In most cases, biodiesel is priced slightly higher than diesel. Biodiesel also has slightly less energy content than diesel, meaning that vehicles with B20 will use up to 2% more fuel than 100% diesel. The October 2006 issue of the Clean Cities Alternative Fuel Price Report included calculations on an energy equivalent basis; B2 to B5 was priced higher than reg- ular diesel by approximately 14 cents per gallon, B20 higher by approximately 9 cents per gallon, and B99 to B100 by approximately $1.02 per gallon. Other costs associated with biodiesel include: • Tank cleaning if required, • More frequent replacement of fuel filters if required, • Biocide and other additives if required, • Retrofitting vehicle and facility fuel system equipment with compatible materials if required, • Periodic fuel testing if required, and • The extra labor needed to effectively manage the biodiesel program. Costs can be offset by tax reductions, grants, and other incen- tives that may make biodiesel close to or even less expensive than traditional diesel. • Incentives In 2004, Congress passed a federal excise tax credit for biodiesel given to the fuel distributor, which is generally passed down to the end user as a way of reducing biodiesel costs. Set to expire at the end of 2008, the tax incentive is expected to be extended through 2017. Another incentive offered by biodiesel allows fleets required to purchase alter- native fueled vehicles under the Energy Policy Act of 1992 the option of purchasing and using biodiesel instead. The Congressional Budget Office and the U.S. Department of Agriculture have confirmed that biodiesel is the least-cost alternative fuel option for meeting Energy Policy Act of 1992 requirements. Other incentives are also available. • Local Requirements Certain states and local governments have their own require- ments for using biodiesel and other alternative fuels. In New York, for example, certain buildings and vehicles are required to use biofuels such as biodiesel to reduce petroleum con- sumption and emissions. Agencies need to become aware of these requirements and incorporate biodiesel as appropriate. As mentioned earlier, the DOE has a website that summarizes the various requirements and incentives pertaining to biodiesel and alternative fuels at www.eere.energy.gov/cleancities/ vbg/progs/laws.cgi. • Public Awareness The EPA first began regulating diesel emissions about 20 years ago, a move long overdue. The black soot and other emissions emanating from exhaust pipes of unregulated diesel engines pre- sented a valid environmental concern. The problem was most visible with transit buses that operated in congested city traffic. Because of this, the EPA established more stringent emissions standards for transit buses than their heavy-duty truck counter- parts. In the 1990s, EPA’s Retrofit Rebuild Program required transit buses to meet more strenuous emissions standards when their engines were rebuilt or replaced; the same requirements were never passed down to the much larger trucking industry. Because most transit agencies are unaware of just how clean diesel bus engines have become, the use of biodiesel gives these agencies an ideal opportunity to highlight the emissions and energy independence benefits offered by bio- diesel. Several transit agencies have done this through public relation campaigns and other efforts. RECOMMENDATIONS There are several recommendations regarding the use of biodiesel. The most significant is that agencies avoid the temptation to simply order biodiesel and start using it. Instead, agencies must first become knowledgeable about the fuel, and develop a program to actively manage its imple- mentation and use.

The following recommendations are based on the synthe- sis findings and are offered as a checklist of sorts to assist agencies with their implementation and use of biodiesel. • Locate a suitable biodiesel supplier to determine avail- ability and cost. Also determine: – If the B100 used to make blends meets the ASTM D6751 specification. – If the petroleum diesel portion meets ASTM D975 and local agency fuel requirements. – The various cloud points for the pure biodiesel (B100) and other popular biodiesel blends such as B2, B5, or B20. – If the supplier is BQ-9000 certified. – How the fuel is blended: Is it premixed (pipe or rack blended), tank blended, or splash blended? – What level of assurances and safeguards are pro- vided by the supplier to ensure that the biodiesel will be properly blended (assuming the supplier does the blending). – The level of after-sales support provided by the sup- plier in terms of fuel-related warranty and other support. – How the supplier will protect against cold weather is- sues: Will the biodiesel be warmed above the cloud point of the fuel at the time of delivery? – If references from other biodiesel customers are available. – If there are additive recommendations to control bac- teria growth and to increase cloud point levels. – How supplier tanks are cleaned to prevent contami- nation of biodiesel during delivery. • Contact engine and vehicle representatives to determine: – Allowable maximum biodiesel concentrations for use in engines and vehicle fuel systems to maintain warranty coverage. – Exactly what the manufacturers will and will not cover regarding warranty and biodiesel use. – The level of risk the agency is willing to take during and after the warranty period if biodiesel is used in concentrations higher that those allowed by vendors. – What materials in the engine and fuel delivery systems are not compatible with various levels of biodiesel; obtain their recommendations for procedures to make materials compatible. – Additive recommendations to control bacteria growth and to increase cloud point levels (prevent fuels from gelling). – If policies concerning biodiesel use and warranty coverage have changed or been updated (check periodically). • Contact facility fuel dispensing equipment representa- tives to determine: – Allowable biodiesel concentrations for use in storage tanks and dispensing equipment. – What materials in the fuel storage and delivery systems are not compatible with various levels of biodiesel; 42 obtain their recommendations for procedures to make the materials compatible. – What additives they recommend to control bacteria, algae, and other microorganisms, and to increase cloud point levels. • From the previous items, you will know how the fuel will be delivered, either premixed by the supplier in the proper concentration, or as B100 and then tank or splash blended at the agency’s site. Regardless of the blending, you will need to develop (or modify existing) fuel spec- ification and contract requirements that include: – Use of ASTM D6751, ASTM D975, and BQ-9000 standards. – A definition for biodiesel to the specification: a fuel composed of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, des- ignated B100. – Consider using the Engine Manufacturers Associa- tion’s test specification for B20. – Check with ASTM periodically to determine if their specification for B20 and other blends has been released; use that specification as appropriate. – Include provisions to have the supplier ensure the biodiesel is not contaminated. – Include the appropriate fuel additives for controlling bacteria and water, and to prevent gelling. – Ensure the contract gives you flexibility to increase or decrease the biodiesel percentage if needed. – Provisions for the supplier to provide the cloud point for B100 or each biodiesel blend delivered; specify that the temperature of the fuel be at least 10°F above its cloud point when delivered. – If delivered premixed by the supplier, include assur- ances that the blend will be homogeneous when delivered, and that the supplier will stand behind the mixture if found to be not uniform. ♦ If delivered as B100, the agency will need to have procedures in place to ensure that the fuel will be adequately blended onsite using proven splash- or tank-blending techniques. Splash bending relies on gravity to do its work; in-tank blending involves some form of agitation such as mechanical mixing or alternate pumping of the fuels (i.e., diesel first followed by B100 followed by diesel). • Based on these findings: – Begin with a conservative approach. Consider first testing biodiesel on a limited number of buses. Initi- ating the project with lower biodiesel concentrations during warmer months may be more appropriate to gain initial experience; work up to the final blend concentration in increments (i.e., B5 to B10 to B20). – Instead of replacing all facility bulk storage with biodiesel for the initial test, consider dedicating a certain tank(s) for biodiesel, installing temporary storage tanks, having the supplier fill vehicles on site (wet hose), or filling at a public filling station if available. Monitor fuel filters and vehicle performance during the initial test.

43 – Depending on test results: ♦ Institute a campaign to replace vehicle fuel system components with compatible materials. For low levels of biodiesel concentrations (e.g., B2, B5, or B10) this may not be needed. ♦ Institute a campaign to install additional vehicle fuel filters including those with improved water separation, if needed. Again, for low levels of biodiesel concentrations this may not be needed. – In preparation for having biodiesel stored in existing facility storage tanks, test the fuel tanks for water and sediment, and clean them if needed. Also determine if any facility fuel storage and dispensing equipment materials not compatible with biodiesel will need to be changed or modified. Change out materials as needed. • As experience is gained with biodiesel use: – Modify facility preventive maintenance inspection program. Monitor: ♦ Fuel filters for contamination and blockage; add fil- ters and/or adjust change-out frequency as needed. ♦ Fuel storage temperatures to ensure they are safely above the fuel’s cloud point; aboveground tanks may require additional fuel heating and/or insulat- ing measures. ♦ Water content, bacteria growth, and sediment de- posits when periodically checking tank levels (i.e., when sticking tanks); drain water from tanks and ad- just fuel additive package as needed; aboveground tanks may require additional procedures because of greater temperature fluctuations and tendency to de- velop more water and bacteria growth. ♦ Fuel quality; take samples (one gallon) after each fuel delivery (B100 or blended fuel) and retain until current batch shows no signs of problems; avoid long-term storage to prevent degradation, use biodiesel within 6 months. – Modify vehicle preventive maintenance inspection program. ♦ Monitor fuel filters for contamination and block- age; add filters and/or adjust change-out frequency as needed. ♦ Take other measures as recommended by engine manufacturer. – Once program proves successful, publicize biodiesel use throughout local community. FUTURE RESEARCH The following research topics are suggested as a result of this study: • Follow-up on biodiesel experiences as more informa- tion is gained. • Examine engine longevity, maintenance, and rebuild experiences associated with biodiesel use. • Conduct additional testing of regulated emissions (e.g., particulate matter, nitrogen oxide, carbon monoxide, and hydrocarbons), especially nitrogen oxide, to determine level of emissions reductions from 2007 and newer diesel engines equipped with particulate matter filters, and from engines with nitrogen oxide emissions controls. • Examine the long-term effects of biodiesel on diesel par- ticulate filters and other emissions control equipment. • Conduct testing of emissions that are not currently monitored to determine if biodiesel combustion creates other harmful pollutants. • Examine effective procedures for blending biodiesel. • Conduct an education program to impart how much cleaner diesel has become over the last 20 years and how biodiesel contributes to diesel’s viability as a clean motor fuel.